The present disclosure broadly relates to printing systems and, more particularly, to designating and printing pixels within an imaging pipeline. Marking engines can override color designations for pixels in an image. In such cases, pixels designated as monochrome can instead be output as composite and billed to the customer as the same. To avoid billing for unexpected resources, such pixels are designated as gray pixels, wherein they are billed as monochrome regardless of composite conversion and output from the marking engine.
Electronic documents are utilized to record, display and transfer information. Such documents can include word processing files, graphical images, spreadsheets, and electronic mail messages. In a conventional network environment, an electronic document can be printed by selecting a print driver from a list of available print drivers within an application used to generate the document. The document is then transmitted to the marking engine corresponding to the print driver. A digital front end (DFE) application receives and processes information from the driver to print the electronic document.
The generation of a page containing imaging data (e.g., pictures, text, etc.) frequently starts at a terminal where a user generates a computer generated graphic or receives a contone image from a scanner. Image data is converted into a highly compressed form using a page description language (PDL), which is sent to a digital front end (DFE) that interfaces with a marking engine. The DFE decomposes the PDL and sends a number of separations of byte maps (e.g., cyan, magenta, yellow, and black) of contone video to one or more interface cards via a suitable protocol employed by the DFE. The PDL is expanded into separations of bit maps, wherein the resultant data is sent to the marking engine. Finally, the marking engine has an interface card which reformats the data into rasters, halftones them in a rendering card, and applies them to the raster output scanner (ROS) for printing.
An assumption can be made that a single color will be employed by the marking engine to create a hardcopy monochrome output of imaging data. In one example, it is assumed that a gray field will be output via placement of a plurality of exclusively black (K) pixels. However, for certain types of marking engines such as that used for liquid or solid ink jet printing, it is sometimes desirable to print neutral gray areas (e.g., fill, sweep, field, etc.) with composite pixels instead of monochrome to provide greater output quality. In such cases, four colors (e.g., cyan (C), magenta (M), yellow (Y) and black (K) are utilized to decrease graininess appearance. For billing purposes, however, it is undesirable to charge customers for composite pixels that were assumed to be monochrome.
What are needed are systems and methods to identify gray pixels within the imaging pipeline and remove them from billing calculations to accurately reflect customer expectations.